Is the DIY lunchbox special as good as the go-anywhere Clif Bar? According to registered dietitian and skier Carrie Gleeksman, who works at Denver’s National Jewish Medical and Research Center, peanut butter and jelly holds up against the high-tech bar. “PB&J is good for skiing,” she says. “Just one sandwich may provide enough energy for a half day.” The caveat, of course, is that she recommends defiling the sublimity of the Wonder Bread–Jif combo with hippie ingredients. “Whole-grain bread supplies good portions of fiber, and natural PB provides monounsaturated fats instead of the trans fats you’d get with Jif,” says Gleeksman. “And any old jam gives you simple sugars,” which are good for energy. We added a few other scientific criteria to see how it holds up.